This invention relates to a device and non-invasive surgical method for treating gastroesophageal reflux disease. More specifically, it relates to an anti-reflux valve prosthesis and associated instrumentation for its peroral placement and in situ fixing at the gastroesophageal junction, to prevent the reflux of gastric contents into the esophagus in the treatment of gastroesophageal reflux disease in a patient.
Gastroesophageal reflux disease (GERD) is the commonest cause of dyspepsia, affecting some 30% of the United States adult population intermittently and some 10% on a continuous and troublesome basis. Gastroesophageal reflux disease produces heartburn, abdominal pain and regurgitation of acid-containing gastric contents into the esophagus and pharynx. It may also lead to alteration of the lining of the esophagus (Barrett""s Esophagus), which may go on to produce esophageal cancer. Current methods of treating GERD include powerful antacid medication therapies and surgical interventions.
Medication therapy with powerful antacids is directed at treating the symptoms of GERD, and is necessarily not curative. Furthermore, medication-based therapies are not always fully effective, as reflux is not prevented and the esophagus may continue to be exposed to gastric content.
Surgical intervention typically involves either open surgery (performed through the abdomen or the chest) or laparoscopic surgery (performed through one or more incision access ports inserted through the abdominal wall), and the re-sectioning of tissue or the implanting of a prosthetic device. Although surgical interventions can be curative, these treatments are seriously invasive and have the attendant risk of such procedures. Despite the risk, the field has been motivated to provide solutions to the GERD problem, which has resulted in the development of a number of surgically implantable anti-reflux valve prosthetic devices. Prior anti-reflux valve prostheses are essentially one-way valves implanted at the gastroesophageal junction using open or laparoscopic surgery. The implanted prosthesis allows normal swallowing to take place in an orthograde manner while preventing the reflux of gastric contents from the stomach into the esophagus.
Examples of surgically implanted esophageal anti-reflux valve prostheses include the devices of: Godin (U.S. Pat. No. 5,314,473) which discloses a one-way, antivalve comprising a flattened tubular part associated with an annular fixing element; and Reich (U.S. Pat. No. 4,846,836) which discloses a bi-directional valve and housing for similar purposes. These devices were developed to be inserted into the gastro-esophageal junction via open or laparoscopic surgery and fixed there. The purpose was to permit the unidirectional passage of ingested materials into the stomach while preventing the reflux of gastric content of the stomach into the esophagus. Typically, these devices require suturing or other means to fix them to the tissue of the esophagus.
Generally, all of these prior devices and methods require surgical invasion of a body cavity and breach of the body membrane in some fashion (e.g., open surgery or laparoscopy) in order to accomplish their utility. However, such invasive surgical interventions are too frequently complicated by problems such as stricture formation, xe2x80x9cgas bloat,xe2x80x9d or recurrent symptoms of reflux disease. Additionally, the results obtained by gross surgical treatment can be technique-dependent and vary significantly from surgeon to surgeon.
In view of the preference for minimally invasive forms of surgery there is a need in the art for GERD treatments that can be fully accomplished without surgically compromising the integrity of a patient""s body membrane. Applicant has invented a peroral procedure for the insertion and implantation of a sutureless anti-reflux valve prosthesis that can address this need. It benefits the field to have an alternative prosthetic device and method that can be practiced to position and fix an anti-reflux prosthesis in place in the esophagus without resort to surgical incision or laparoscopy.
The present invention relates to an anti-reflux valve prosthesis system for treating gastroesophageal reflux disease (GERD) in a patient, which does not require open or laparoscopic surgery to implant. The present invention provides for perorally inserting a sutureless anti-reflux valve prosthesis down the lumen of the esophagus, to the gastroesophageal junction, where it is fixed in place. The advantage of this system is that peroral insertion of such a valve eliminates the need for either open formal laparotomy, thoracotomy or a laparoscopic approach using multiple access ports. Peroral installation of an anti-reflux prosthesis has the potential benefit of reducing the trauma, morbidity and hospital stay associated with implantation of anti-reflux valve prostheses relative to other surgical techniques. Furthermore, a system permitting the implantation of a standardized anti-reflux valve in an accurate and reproducible manner has the potential for providing more consistent clinical results than can be achieved with other techniquemethods of treatment.
A preferred embodiment of the present invention provides a prosthesis comprising a cylindrical housing, a mounting ring and a one-way anti-reflux valve. The cylindrical housing is constructed of a memory material that can be fixed in the distal esophagus. The mounting ring and the anti-reflux valve are fixed within the housing.
Similar cylindrical devices have been used (without the incorporation of an anti-reflux valve prosthesis) in the treatment of strictures due to esophageal cancer. An example of such a device is the WALLSTENT(copyright) esophageal endoprosthesis (Schneider USA, Inc.). These devices typically comprise a cylinder of memory metal in close contact with a sleeve of suitable material, such as silicone. The prosthesis is inserted perorally and positioned using an adaptation of the usual tool used for installing similar cylindrical devices. The prosthesis is fixed in place by the expansion of the cylindrical device housing the anti-reflux valve.
Another embodiment of the present invention provides an anti-reflux prosthesis comprising a cylindrical housing having an enlarged upper end, an optionally enlarged or bell-shaped lower end, and an interior defined by an interior wall. The cylindrical housing is constructed of a memory material having a normal cross-section. When a force, applied to the housing to make the cross-section small, is removed, the housing returns to its normal cross-section, or is expandable to its normal cross-section, e.g. by a balloon. A mounting ring is fixed to the interior wall of the upper end of the housing. Depending from the mounting ring within the interior of the cylindrical housing is a one-way valve. The present invention further comprises an optional anti-inversion support having two ends, one end of which is fixed to a lower end of the one-way valve and the other end of which is fixed to the wall of the lower end of the cylindrical housing.
Another aspect of the invention is the provision of a system for peroral insertion and mounting of the ant-reflux valve prosthesis in the gastroesophageal junction. The system includes an overtube for holding the cylindrical housing in a radially compressed condition at a distal end of the overtube for peroral insertion down an esophageal lumen. A stylet indwelling in the overtube is in releasable operative engagement with the housing to eject the housing from the distal end of the overtube. A balloon is preferably disposed at a distal end of the stylet within the cylindrical housing, wherein the balloon is in fluid communication with a central longitudinal passage in the stylet for introducing fluid into the balloon to facilitate expansion of the housing to its normal cross-section following ejection of the housing from the overtube, and for removing said fluid from the balloon to allow retraction of the balloon from the housing into the overtube.
In a further aspect, the invention provides a method for perorally implanting an anti-reflux valve prosthesis for treating gastroesophageal reflux disease before esophageal cancer. The method comprises: (a) perorally inserting the anti-reflux valve prosthesis described above in a radially compressed condition down the esophageal lumen: (b) positioning the compressed anti-reflux valve prosthesis near the esophageal junction; and (c) expanding the anti-reflux valve prosthesis to normal cross-section to implant said prosthesis in the esophageal junction. The insertion is preferably effected with the valve prosthesis in an overtube, the positioning preferably includes ejecting the valve prosthesis from the overtube, and the expanding optionally comprises inflating a balloon inside the valve prosthesis.